The present invention relates to an injector with high atomization capacity, controlled electromagnetically, of the single-jet air-assisted type, for the supply of fuel to an engine of a motor vehicle.
In particular, the present invention relates to an injector of the "Pico" type, capable of atomizing the fuel by injecting it through a distributor element capable of producing an outflow through a thin wall.
There are known electromagnetic injectors for supplying vehicle engines in which the injection of the fuel is regulated by an electromagnetic actuator which controls the movement of a stop valve capable of controlling the formation of jets of fuel through atomization holes provided in a distributor element. When the fuel is made to flow out through holes whose length is much less than their diameter, aero-hydrodynamic effects occur in the liquid, atomizing the fuel until it is reduced to very fine particles. By decreasing the thickness of the wall of the distributor element to dimensions of the order of tenths of a millimeter, fuel particles with a diameter of 180-200 micrometers may be obtained. It is difficult to provide more thorough atomization, since a further reduction in the wall thickness is associated with difficulties in construction and problems with clogging and excessive wear of the holes in use. However, there are known devices for improving the atomization of the fuel, in which the atomized jet of fuel is mixed with an auxiliary air flow before being injected into the combustion chamber.
However, the atomizing action obtained with these injectors is not very thorough; moreover, these injectors, because of their structure, have a rather brief service life, generally showing phenomena of rapid wear.